Lock joint for anatomical appliances



M. E. CHRISTOPHER LOCK JOINT FOR ANATOMICAL APPLIANCES Oct. 18, 1949.

2 Sheets-Sheet 1 Filed April 1, 1947 INVEN R.

M. E. CHRISTOPHER LOCK JOINT FOR ANATOMICAL APPLIANCES Oct. 18, 1949.

2 Sheets-Sheet 2 Filed April 1, 1947 Patented Oct. 18, 1949 UNITE D ST ES PAT OFF l-C E.

LOCK J (DIN 1 FORANATOMICAL APPLIANCES Merle,E.'.GhristoplienELPaso, Tex.

Application April, 1947, SerialNo'; 738,610

5 Claiins; 1

My present invention relates to; prosthetic. or anatomical devices, particularly to. leg; braces? and artificial legs and it has for its objectto provide a lock for the articulatedpartstof such appliances which is opera-ted hydraulically'whenthe weight of the wearers bodyv may require tobe fully sup-- ported.

Another object of my invention. is to provide an hydraulic lock for joints of leg. appliances which is automatically operated by the wearer.

in his application of more or less of. his bodily I weight as he changes from'asittingto a'standing. position, or as he may shift his-weight. fromtoe to heel in walking.

Furthermore, my invention comprehends the. incorporation, with thev joint of an. anatomical leg appliance, of an hydraulic locking'mechanism in combination with an actuator incorporatedinthe shoe of the wearer forcreating an operating; fluid pressure controllable by thewearerls. foot A still further object of the invention is. the provision of an automatically operated hydraulic lock as an element. of ajointed connection for anatomical appliances. which isactuated by a: piston in the heel of the. wearers shoe when-he. variously appliesthe weightv of hisbody thereto as in rising to an erectpositionor in theusual. action of stepping forwardly...

To these and other ends my invention comprises further improvements and. advantagesmas will be further described. in the. accompanying. specification, the novel featuresthereofibeing.set. forth in the appended claims.

In the drawings:

Figure 1 is anelevationalviewoiamanatomical. leg brace illustrating one adaptation-ofimyin? vention.

Figure 2 is a front elevation taken at right angles to Fig. 1.

Figure 3 is an exploded view showing the various elements of the hydraulic lock. di'sassociated.

Figure 4 is a. horizontal.crossisectional view taken on the line 44 of Fig. 1.

Figure 5 is a vertical central. sectional View through the actuator taken on. the line of Fig. 1.

Figure 6 is an exploded view showing, in their disassociated relationship, the several parts oithe actuator.

Similar reference numerals, in;v the several figures, indicate similar parts.

My invention is applicable to a wide variety of joints employed on braces and artificial legs and for simplicity in illustration I have shown a joint correspondin'g'tothat of a human knee. and forming-Stine. point of articulation between upper and lower brace members, which in'practice' are: connected: to. like? portions" of a person's leg. to f'ormasupport"therefor.

Sucha: brace comprises an upper arm Ill, provide'd'withithe-usual padded leg encircling straps; H and". I2; and the lower arm l3 having at its lower endra laterally projecting extremity M de-- signed to extend. beneath the instep of a shoe Wand toi'be moreor less rigidly connected tothe shoe; Incarrying out my invention I provide a special form. of connection between said arms. On; one of'them, for instance the. lower arm I3, I provide: an outwardly extending hub 16; The. lati'imt is slotted as: indicated at IT across its top and at its rear side: in the plane of the outer face-of the arm; a continuation of which forms a: bottom I 8' in the hub which has a centralthreaded: aperture for a securing stud IS. The top end of: upperarm' l0isi in vertical alinement with. the: lower end I4 of the lower arm but in ordento better simulatev the action of the wearers knee joint, I incline the lower end of arm I0 forwardly andprovide it with a reversely curvedv neck 25. This neck extends into the slot. I1 and carries-a cylindrical head-fitting within the hub l6: The-head is cup-shaped, having a rim 26 and. a bottom 2'! the outer face of which rests in. frictional engagement with the bottom [8 with-in hub H5. The bottom 21 is also provided with. a circular central aperture 28 for the receptionof the securing stud 19. The actual bearing-:by which the-arms l0. and I3 are pivotally connected.comprises/inner and outer ball races 29-31]: carrying anti-friction balls 3 I. The outer raceway or ring- 3.0. fits closely within the rim 26 and-theinner raceway 29- is carried by. the bearing. stud. l9; Fitting within the: hub l6 and extendingiover the ball raceways is. a pressure disc 32-whichis flatonone faceand on its other side has a central cavity accommodating the head of the stud.

The hydraulic operating element of the joint connection: comprises. a flat expansible chamber 35,. preferably made. of rubber. It is circular in outline. snugly fitting within the hub 16, and" having; a tubulan neck- 36 which passesthrough an.- aperture: 31 located'in the lower side of the hubmpposite: the. slot l 1'. The: chamber occupies the-space:between. the; inner pressure disc 32- and the inner side of a cover plate 38 which is removably screw threaded into the outer end of the hub I6. From this arrangement of parts it will be seen that, by inflating the chamber, pressure is exerted laterally on the one side against the cover plate and on the other side against the pressure plate, to frictionally lock the parts of the joint primarily by forcing together the broad contacting faces on the two arms, one of which is the inner bottom of the hub, the other being the outer portion of the head carrying the ball races.

The actuator for creating the necessary pressure in the aforementioned chamber 35 may be any suitable device connected to the neck 36 thereof. In order, however, that such action may be automatic I have provided a cylinder-piston mechanism, generally indicated as 40 in Fig. 1, which is connected to the chamber by a tubing 4| and is designed to be operated by the user applying thereto a certain proportion of the weight of his body.

located between said closure and the end of the To the above described end I place in a cavity of the heel of the shoe l 5 a cylinder-piston combination, the cylinder member comprising a circular base 42 by which it is secured firmly in position, on which there is a rim 53 of a height substantially that of the thickness of a shoe heel. Within the cylinder is the piston M the outer face of which projects beyond the cylinder rim. On the inner edge of the piston there is a flange 45 fitting closely within the cylinder beneath a retaining ring 46 thereon. Between the bottom of the cylinder and the piston there is an elastic hollow body 41. It is preferably made of rubber and is circular and rectangular in cross section and fits closely the interior dimension of the cylinder and serves to yieldingly hold the piston normally projected and permit it to be forced inwardly of the cylinder. The body 41 is a substantial duplicate of the chamber 35. It has a tubular extension 48 at one side which leads outwardly through an opening 49 in the rim A3 and a corresponding passage formed in the shoe heel.

In practice the chamber 35 and the elastic body 41 are filled with a suitable fluid and are connected by the pipe M, as shown in Fig. 1, which may be either a rigid or a flexible tubing securely united at its extremities to the neck 36 and the extension 48.

It will be readily appreciated that the form of ball bearing joint and the means for locking it either automatically, or accomplishing this result under control of the wearer of the appliance, as comprehended by my invention, is applicable to various types of joints used in connection with anatomical appliances. In the form of joint illustrated it will be seen that when the person to whom the appliance is fitted is in a standing position he can apply sufficient weight to compress the fiuid in the hollow body 41 which reacts by the resulting expansion of the chamber 35 to securely lock the arms in and I3 together. By shifting his weight slightly he can also release the pressure on the lock to any extent desired.

I claim:

1. In an anatomical appliance embodying upper and lower brace members, a tubular hub on one of them receiving the adjacent end of the other, a pivot connecting said members, and an expansible chamber enclosed within said hub, of a hollow compressible actuator located in the heel of a shoe worn by the wearer of the appliance and a conduit connecting the chamber and second member, and means for forcing fiuid under pressure into said chamber to lock the arms in frictional engagement.

3. 'An anatomical appliance comprising two articulated members, the pivotal point thereof embodying a closed hub portion, an expansible chamber located in the hub and bearing on the pivot,- of a hollow compressible body connected to said chamber and forming therewith a variable' fluid pressure mechanism serving to produce friction on said pivot, said compressible body being adapted to be compressed upon the application thereto of bodily weight of the wearer of the appliance.

4. In an anatomical appliance, the combination with leg brace members comprising a lower arm having a laterally extending tubular hub and an upper arm having an end extending into the hub and engaging at one side with the bottom thereof, ball bearing raceways within the hub carried by the other side of said arm and a stud uniting said parts for relative pivotal move!- ment, of a closure for the outer end of the hub, an expansible chamber located between the closure and the bearing parts and means for forcing fluid under pressure into the chamber to frictionally lock the brace members together.

5. In an anatomical appliance, the combination with two brace arms having overlapping ends, one of them having a tubular hub enclosing the extremity of the other arm, a pivotal connection for the arms located within the hub, a closure for the outer end of the hub, and an expansible rubber chamber within the hub, an actuator comprising a cylinder adapted to be arranged in the heel of a shoe worn by the wearer of the appliance, a piston in the cylinder and a said body and chamber and forming in combination therewith a hydraulic system for regulating the frictional engagement of the parts of the arms joint.

MERLE E. CHRISTOPHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,175,136 Stewart Oct. 3, 1939 2,305,291 Filippi Dec. 15, 1942 FOREIGN PATENTS Number Country Date 523,329 France Aug. 17, 1921 530,887 France Jan. 3, 1922 

